Friday, 28 September 2012

3310 LCD and the Raspberry Pi

The LCD display is very crude. However it consumes very little power, is cheap to find. It is also well supported in the Hack/Maker comunity. A small display may be usefull for initial setup or status monitoring of mobile, battery driven projects. For example it could show IP address to allow WiFi connection or could display nuber of pictures taken on an automatic camera.

There are plenty of projects relating to the LCD display found on 3310s and other phones. I purchaced some PCB sockets to connect to the IO pins of the raspberry pi from EBay.

These can be placed on the IO pins. Wires can be easying soldered to the connector before they are connected. This is ugly, but ideal and cost effective for Raspberry Pi "projects".

To talk to the LCD display you need two GPIOs and some SPI. The LCD required an addition capacitor that I fitted and the connector end of the cable. The display will just about run from the 3.3 volt supply on the IO pins but I suspect this will be the only thing you can power from this supply.

I soldered directly onto the display, this was VERY fiddly. I used standard ribbon cable, others suggest using the FFC style (Flat Flexable Cable) that can be found oinside discarded electronics such as CD dirves.

I used the "wiringPi" project for my GPIO, SPI and timing. I used one of the many AVR based LCD drivers, (I will try and post more info).

To get the SPI driver to appear I needed to edit a system file to remove the SPI from a "blacklist". Google this for now, I will try and find the link and add it here.

GPIO and SPI appear to only work if you run as su. I created a su login using the sudo passwd command to make this easier.

CONCLUSION: So far I have demonstrated that with the LCD display can be driven from raspberry Pi with only the addition of the 4.7uF capasitor. The Rapberry Pi will power and control the display. The displayed results were not as expected. This is due to known issues in the way I have ported the code from AVR to Raspberry Pi. The project is still WIP. I will try and post updates and perhaps some code when I have it working better.

Friday, 14 September 2012

Raspberry Pi Web Server Apache2

With the latest Raspian updates, Apache2 installed seamlessly using sudo apt-get install apache2 I had googled its installation but most of the advice in the walk throughs is not needed now. I hope to get some of the more advanced features, such as scripting and databases, working. This may require more installation. Out of the box apache dishes up the default HTML page without any configuration.

Raspberry Pi and the Chromium web browser

On an updated Raspian you can install Chromium web browser. This beautiful eye candy shows off web pages, such as the BBC web site, in their full glory. However the performance out of the box is very poor. I'm on the hunt for some information to improve the performance. Perhaps a later release or better settings.

Saturday, 8 September 2012

Raspberry Pi laptop.

Watch "Raspberry Pi Laptop with Atrix 4G Dock" on YouTube

Update: 29th September 2012.
I have acquired a lapdock from eBay. I'll hopefully create a new post about it. The cables I ordered have arrived today.

Play flash videos in Midori

This post describes a simple way to get flash video, such as YouTube, working in the midori browser. I must check this out. I think raspbmc has a YouTube plugin, but this is YouTube in a raspian browser.

Raspberry PI ‘RaspianHOWTO Play Flash in Midori | Lance's Blog

UPDATE: 17th September 2012 I tried this over the weekend. It is easy to do and seams to work. However the performance is poor. If your keen to see YouTube on your Pi I suggest tring XBian or Raspbmc.